1. Field of the Invention
The present invention relates to three dimensional display apparatus, and more specifically, to display apparatus and display method for displaying three-dimensional images using a parallax barrier system.
2. Description of the Related Art
Conventionally, a parallax barrier system has been known as a method for achieving a display of three-dimensional images without using special glasses. A display device using a parallax barrier system mainly includes a display device that displays a left eye image and a right eye image alternately every each vertical line, and a parallax barrier that is placed in front of the display device that selectively shades light emitted by the display device. Such a display device allows a viewer to view a three-dimensional image by making the left eye image visible only to the left eye of the viewer and the right eye image visible only to the right eye of the viewer through slits formed between each barrier of the parallax barrier.
For example, Laid-open Japanese Patent Application No. 9-197344 discloses a display device in which barriers extending vertically are arranged at a regular interval using a liquid crystal panel to form a parallax barrier between a liquid crystal display (LCD) panel and a backlight. Further, the parallax barrier can be moved in a lateral direction in a designated amount (barrier movement). In such a structure, enlarging a visible range of a three-dimensional image in a lateral direction of the LCD panel is possible by optimally controlling the barrier movement as well as the switching between the right eye image and the left eye image displayed on the LCD panel.
However, in the conventional structure mentioned above, there are problems in that while a visible range of three-dimensional images in a lateral direction can be enlarged, a three-dimensional view is not possible when the distance between the viewer's eyes and the displayed image (such as the LCD panel) deviates from a predetermined preprogrammed distance. This is because an area on the LCD panel at which the right eye image is displayed does not completely correspond to an area on the LCD panel that can be viewed by the viewer's right eye through slits of the parallax barrier, and, in a similar manner, an area on the LCD panel at which the right eye image is displayed does not completely correspond to an area on the LCD panel that can be viewed by the left eye of the viewer.